Oil & Gas
| Wed 15 Jul 2026
Beijing, July 15 -- Petrochina Co Limited has filed a patent application for Multistage Sealing Ball Valve. This invention was developed by Jiao Bin, Zhang Hao, Wang Jia, Liu Dongbin, Zhang Xudong, Xie Ting, Kang Xiaoping, Wei Wenxi, Li Jingxiong, Xu Xianwei, Guo Zhongming, Wang Guolu and Li Hongxing.
The patent application n..